Europium Induced Alloy Corrosion and Cracking in Molten Chloride Media for Nuclear Applications

ABSTRACT Molten chloride salts can be corrosive to the structural alloys used in nuclear applications where they have been considered as advanced coolants and electrolytes. This paper investigates the corrosion of Alloy 709 and Inconel 718 in KCl-LiCl-EuCl3 molten salt. Europium is found to be very corrosive in chloride salts, which results in the rapid release of ionic nickel and iron corrosion products, and formation of oxide byproducts of Cr2O3, FeCr2O4, and NiO in the melt. Alloy 709 suffered uniform corrosion of 35 µm in 120 h, while Inconel 718 was thinned by >86 µm with severe cracking and void attacks.